Lathe-chuck.



PATENTED' MAR. 2o, 1906. G. B. t'nnLfm;v 1 LATHB GHUGK; lAIPLIOATIONFILED JAN. 3Q. 1905.

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UNITED sTATEs PATENT OEEIO'E.

. GEORGE BEN J A TAYLOR,

LATHE- Specification of Letters Patent.

Patented March 20, 1906.

Application filed January so, 1905. 'serial No. 243,372.

To all whom t may concern,.- l

Be it known that I, GEORGE BENJAMIN TAYLOR, engineer, a subject of theKing of Great Britain, residing at 4,3 Bartholomew street, Birmingham,in the county of Warwick, England, have invented certain new and usefulImprovements in Lathe-Chucks, of which the following is a specification.

This invention is an improved lathe or like chuck particularly adaptedfor holding bars for machining, it being characterized by the followingimproved features:

The chuck-body has formed within its bore a' number of axial and radialslots or recesses within which lie a number of gripping-jaws a jaw ineach slot. The ljaws are adapted to move in the slots radially. vTheouter surface of each jaw-viz., the surface nearest the bottom of theslot or recess-is tapered in respect of the chucks axis. Also withineach slot or recess inward of the jaw is provided a wedge-shaped ieceadapted to move approximately paralle with the chucks axis. One of thefaces ofthe wedge-shaped pieceuis the counterpart ofthe taper on the jawaforesaid, while another face rests hard upon the bottom of the outersurface ofthe slot or recess, which said bottom is approximatelyparallel with the chucks axis. A partly-rotatable or rotatable ring isfitted within the chuck body inward of the wedge -shaped pieces, thisring being concentric with the chucks axis. The rotation of this ring isadapted to move the wedge-shaped pieces collectively, it having,preferably, upon it camshaped pieces which operate against the backs ofthe wedge-shaped pieces to move thesaid pieces in one direction toradially move the jaws. The ring is partially rotated, preferably, by ascrew applied to the body of the chuck and having between it andthe'said ring a loosely-applied steel piece. A spring is applied to thebore of the chuck to keep the jaws from falling out of the recesses 4andto help the release of the grip of the jaws on a bar, the inclinesbetween the jaws and wedgesha ed pieces, and also between the said wege-shaped pieces andthe cam'projec tions of the ring, being pitched mostconveniently for this releasing.

A practical carryingout of the invention is represented in the drawingsherewith, upon whichy Figure 1 is a longitudinal sectional elevationFig. 2, a front elevation, partly insection, with the end plate removed;Fig. 3,

a front elevation of the cam-ring separate, and Figs. 4 and 5 sideelevations of the said cam-ring looking in dierent directions.

In the drawings, 0, is the hollow cylindrical body of the chuck, in thebore of which are with the chuck s axis. These slots or recesses formguides or ways for three grippingjaws c c c, which are adapted to movetherein radially inrespect Of the center'of the chuck. The outer surfacec2 of each jaw is tapered or inclined to the axis of the chuck, whilethe inner surface c3 is adapted to grip the bar or are ticle to be heldby the chuck:

A wedge-shaped piece d is provided in the ment in thel slot or vrecessparallel with the axis of the chuck. The face or surface d2 of thewedged is correspondingly inclined or tapered to the taper surface c2 ofthe j aw,while the face of surface d3 is parallel with the axis of thechuck and slides hard upon the bottom a3 of the slot or4 recess, so thatwhen the wedge-shaped piece is moved in the said slot or recess theparticular jaw it is'behind is moved radially in the said slot orrecess.'

Within a recess e in the chuck-body a is loosely fitted a ring e2, whichhas upon its one face three cam projections e3 e3 c3. This ring isadapted to be partially rotated within the recess e, so thatl its camprojections work against the ends d of the wedges d, these ends d6 beingpreferably correspondingly inclined or shaped to conform to the said camends of the wedges normally touch, so that a smallamount of rotation ofthe ring e2 causes a movement of the wedges, a feature of the inventionbeing that the whole of the wedges are moved by the ring together and atthe same time.

The ring e2 is partially turned in the recess e by means vof a screw f,which works through the body of the' chuck, preferably at a tangent.- Itis deirable to use a hardened-steel bush f2 in the chuck -Ibody toprovide the s crewebox for the screw-f. The ring e2 is cut away at g(see Figs.v 2 and 3) to provide an abutment g2 approximately at rightangles to the axis of the screwf, this abutment for the one and roundedend h2 of a steel piece h to contact. a'semicircular recess into .whichthe said one provided three rectangular-shaped slots or revcesses 0,2 a2a2, arranged parallel and radially slot or recess at the back of eachgripping-j aw c, this wedge-shaped piece having a moveprojections. Thecam projections and 'thel The said abutment is formed with.

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end h2 projects, while the end of the screw f is also formed with asemicircular recess f, into which the other-and rounded end h of thesteel piece rits. A

The ring e2 may be prevented 'l'rom any other than a rotating movementby any suitable means; but preferably a plate or adapter 'i is provided,which is bolted to the body of the chuck at and to the lathespindle noseat x2.

On the front end of the chuck is provided a removable plate y, whichforms an abutment for the jaws c at their forward ends, this 'platebeing screwed tothe body of the chuck at y2.

A band-spring m is iitted to the bore of the chuck for the purpose offorcing the jaws c radially out when the pressure from the screw f isreleased, this spring, although within the gripping-bore of the chuck,beingbehind the gripping-surfaces of the jaws.

To move the jaws inward to grip, the screw f is operated to partiallyrevolve the ring e2, and thereby move the wedge-shaped pieces in theways a2 in the direction of the arrow, Fig. l. fromv the screw isreleased the spring m comes into action to push the wedge-shaped piecesin a direction reverse to the arrow, although the inclines between theparts by their pitch help this movement.

The gripping-jaws c are interchangeable by taking off the plate y andremoving the springs m, Fig. 2, showing jaws suitable for asmaller-diameter bar.

Immediately the pressurev The invention is not restricted to theparticular construction and operation ol the. ring c2, as the said ringmay operate 'upon the wedge shaped pieces from a screw acting within therecess in which it is provided, the said ring being either internally orexternally screwed to move within or over a screwed part of the body.

Any number of gri pping-j aws c may be pro vided in the chuck-body witha like number of wedge-shaped pieces, but a single ring c.

Having now described my invention, what I claim, and desire to secure byLetters Patent, is-

In a chuclefoi a lathe or similar machine, the combination of a hollowcylindrical body having rectangular-shapcd slots or recesses arrangedparallel-to and radially with respect to the chuck-axis, grippingj awsradially slidable in the slots or recesses and having outer inclinededges, wedges disposed in the outer portions of the slots or recessesand having inner inclined edges engaging the inclined edges of the jaws,and a rotatable ring having cam projections thereon held in contact withthe ends of the wedges.

In testimony whereof I have hereunto set my hand in the presence of twosubscrilnng witnesses.

GEORGE BENJAMIN TAYLOR.

IVitnesses:

GEO. FUERY, H. Davis.

